Fixed or mobile machines may experience performance degradation over time if not periodically maintained and repaired. Often the machines are in remote locations or are expensive to remove from operation. Thus, it is desirable to keep such machines in operation as much as possible, and to minimize their downtime.
Periodic scheduled maintenance is one way to reduce downtime due to repairs, or otherwise minimize the impact on operations. However, periodic maintenance may be undesirable because the maintenance is done on a schedule, not when the maintenance is actually needed, thereby leading to excessive downtime. Another approach which reduces the downtime of a machine is to monitor the machine components, trend over time any data collected, analyze component or machine behavior, and schedule maintenance as problems arise or are anticipated. The trending and analysis may be done locally by the machine and/or may be performed at a remote location. In this manner, maintenance routines can be deferred until needed.
When monitoring machine components, accurate and complete data generally improves the diagnostics and prognostics. One deficiency in conventional monitoring and trending practices is in the use of temperature sensors. A temperature sensor can only report the temperature at its specific location, and not of the entire structure or body that is being monitored. In contrast, thermal images provide data on the entire body or structure. A thermal image shows temperature variations in a relative sense with respect to other temperatures and temperature differences between thermal intensities. Thus, it is desirable to combine temperature and thermal data to provide calibrated thermal images that allow the prediction of the temperature at all locations of the entire structure or body.
One example of a system that reports temperatures of sections of a turbine engine is disclosed in U.S. Pat. No. 6,691,019 (the '019 patent) issued to Seeley et al. on Feb. 10, 2004. Specifically, the '019 patent discloses a temperature sensor on each section of a turbine case for calibrating infrared images of the case. The '019 patent discloses a system for controlling distortion of the turbine case. The system includes obtaining a temperature distribution, which includes a plurality of infrared images of the turbine case. The '019 patent discloses a system for calibrating the infrared images using the thermal data including using a plurality of temperature sensors positioned on the turbine case to obtain thermal data. In addition, the '019 patent discloses a computer configured for modeling the thermal stresses.
Although the system of the '019 patent may help calibrate an infrared image of a turbine case, the system may still be problematic and have limited applicability. Specifically, the temperature sensors of the '019 patent are outside the turbine case, which may limit the accuracy of the data obtained by the temperatures sensors. In addition, the method and system of the '019 patent are not in real time or located at a remote monitoring facility. The '019 patent also may not allow for predictive scheduling of routine and/or emergency repairs and maintenance. Moreover, the '019 patent is limited to redesigning turbine cases or configurations and does not allow for calibration using predictive models of nonsymmetrical structures or non-turbine structures.
The disclosed method of correlating thermal sensors is directed to improvements in the existing technology.